Steam-engine with piston-controlled exhaust-ports.



J. STUMPP.

STEAM ENGINE WITH PISPON GONTBOLLED EXHAUST PORTS.

AYPLIUATION FILED PEB.19,1810.

Patented Jan. 24, 1911.

n o Y mfg' UNITED sratrizs PATENT oFFIcE.

yJ'HANN STUMPF, 0F BERLIN, GERMANY. y

"STEAM-ENGINE 'WITH PISTON-CONTROLLED EXHUST-PORTS.

lTo all whom t't/may concern:

`Be it known that subject of -the Kin of Prussia,`and resident,

of 33 Kurfrsten amm,` Berlin, Germany, professor, have invented certain new and useful Improvements in Steam-Engines with Piston-Controlled Exhaust-Ports, of which the following is a specification.

This invention relates to steam engines and especiallyto those intended for locomotives, and is an improvement 4on that 4type of engine, in which the exhaust takes place through ports in the cylinder walls which are controlled by the piston while the admission takes place through separate ports controlled by valves.

In locomotive engines an important consideration as is well known, is sureness andsafet'y in operation and for this purpose it is necessary that the working parts be loaded as little as possible.

In engines-0f `the t'ype above referred to 4the simplifica-tion of the valve mechanism by the omission of all valves for controlling the exhaust increases the safety and sureness of such englnes and the valve gear 1s relieved toa considerable extent since only the working parts.

inlet valve requires to be operated. On the other hand however the compression is greatand this causes a vconsiderable stress on the The"disadvantageous etlect of this stress is most objectionable when the engine is running with no load as 'in such a case the compression has little or Ino purpose.

In locomotive engines it, isknown that when running'down hill or running with no load the compression 'above referred to is not only objectionable but the inlet valves arev operated by the valve gear without producing any etl'ect on the engine.

According to the present. invention the arrangement is such that during no-load running the inlet valves are retained open so that both ends oli the cylinder are t'recly connected and the air( or steam in the cylinder merely tiows back andl forth from one end of the cylinder tothe other while no great compression occurs. rlhe parts are not vtherefore stressedand in addition the inlet v valves which are retained open, are not at. all

lhe life of the.

atleeted by the valve gear. engine 1s naturally very much increased by .relieving the parts o'l the stresses above referred to and also by placing the valves out of operation during down lull running. The advantage of placlugthe valves out of opsxiecincation of Letters Patent. Application led February 19, 1910. Serial No. 544.733.

Patented Jan. 24, 1911.

y eration will be readily appreciated when it I, JOHANN STUMPF, a l 1s taken into consideration that during down hill running the speed is usually very considerable. n

'lhe invention is illustrated in the accompanying drawings, in which:

Figure l is a sectional eleratipn through `the cylinder of an engine provided lwith means for retaining the4 inlet valves open according to the present invention, Fig. 2 is an enlarged detail of the valve and the operating mechanism for opening itl and retaining ity open as desired. Fig. 3 illustrates a -unodited construction.

'lhe engine cylinder a is provided with exhaust ports l) which are controlled by the piston c in its travel. is controlled by valves rl having rods e adapted to be operated by rollers ,h which lcoact with curved cam-pieces i carriedY by The rollthe sliding shoes; on the rods e. ers /L are carrie by a rod g adapted to be reci nocated by means of jany suitable ear oi which one link t is illustrated. Steam is supplied through a pipe 11 and this pipe is provided with branches 1- which lead to the valve chests at each end of the cylinder a. It will be understood that the stop valve for opening and closing the suppl of .steam tothe engine shpuld be arranged7 on the boiler side of the T-piecc 'n'.

v',lhe valve (I is shown as a balanced valve guided on a central sleeve d (see Fig. 2). W'thinA the sleeve el there is arranged a in k having a part la which when thevpin is raised by the finger lever m, raises the valve (Z. When the valve d is raised, the cam piecez' .in Fig.` 1 is also raised yout. of the path of the roller h. so that the reciprocation of The steam admission the rod g does not produce any effect u on the valve (Y. It wi-ll be seen now that w en the valves Z (l atI each end of the cylinder have beenraised by operating the levers m, the steam or air in thecylint er o. will pass back and forth from end to end, past the valves (l and through the pipe '1". In former' constructions when the valves were not reports b. As is well known the ports b in locomotives `open into the chimney draft pipe, so that this suction-actionwas apt to suck sot or grit into the cylinder. By the arrangement according to the present invention no such suction can take place especially if the pipe r is of sulicient cross section. p i v Instead of opening the valve d by. means ,of a lever it may be opened by steam pressure f,or instance in the manner illustrated in Fig. 3. In this case a steam pipe l2 leads i to the sleeve d in which there works a iston d?. When pressure steam is supp 1ied,

through the pipe (l2, the piston or plunger (l3- 4 haust ports midway in the length thereof, a

.working piston in said cylinder arranged to over-run and control said exhaust ports at i and neareach end of its travel, a steam chest at each end of said cylinder, a connection between said chests, a steam supply pipe, a stop valve, interposed bet-Ween said steam supply pipe and saidconnection between the chests, a Valve 1n each steam chest, means for opening and closing said valves alternately, and additional means for holding said valves open simultaneously and independent-1y of the first-,mentioned openi ing and closlng means. Y I

2. In combination, a cylinder having exhaust ports' midway in the length thereof, a

Working piston in said cylinder arranged to y over-run and control said exhaust ports at and near each end of its travel, a steam chest at each end of said cylinder and having an V`inlet port leading to the cylinder, a connection between said steam chests, a steam supply pipe a lstop valvel between said connect-ion an yinlet valve in each stem chest and control'- ling said inlet ports, a stem on said valve extending in both directions therefrom, means cooperating with one end of each of said stems to open said valves'alternately, and

additional means coperating with the other ends of each of said stems to maintain both valves open simultaneously and independfently vof said first mentioned means.

In witness whereof I have hereunto set my hand inthe presence of two Witnesses. JOHANN STUMPF.

Witnesses:

l- EDWARD Massimi, KARnHANsEN.

steam supply pipe, an 

